[OSM-talk] Server slowness

[Nick Hill]

Looking at the disc usage for the db, 10% of the hard disc was filled with data 
between 29th Dec and 5th Jan. This represents 4Gb of data, including indexes, 
which represents a 25% increase in the total OSM data set.

I have taken a look at the Africa coastline. It is very detailed, and looks like 
it even details mangrove swamps etc. So it is not beyond possibility this 
increase in data set is caused by African coastline.

This could cause a substantial hit for queries hitting Europe. Our database 
currently narrows the index down on either lat or lon, not both. Therefore, 
look-ups for Europe may require brute force searches to remove the African 
coastline from the indexed dataset. That would impact performance until we move 
to a tile based index.







Nick Hill wrote:
> It is still worrying me how the database load has shot up on 30th December. This 
> inevitably causing slowness.
> 
> When did the Africa coastline import run from/to?
> How many points were involved?
> Was there any publicity of OSM on that day which could have led to a significant 
> increase in users? Would this result in this profile of usage ? (I think not but 
> prepared to debate it).
> 
> Steve, did you make any changes to the API or DB set-up around that time?
> 
> 
> 
> 
> Andy Robinson wrote:
> 
>> I thought it was probably the Africa Coastline stuff too. We had nearly half
>> a million node writes a day going in earlier in the week, but as you point
>> out that situation has declined now. The only other thing that springs to
>> mind is Steve's mapnick db rendering. I'm assuming that's coming off the db
>> direct rather than using the last planet. If this is the case I presume then
>> it will take a while for the first run of tiles to be completed, after that
>> the load should drop of course.
> 
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